Stage 2 (Problem 10) - For this multiple choice problem students click the answer and it does not advance them to the next problem. Also, I would suggest not providing them a choice of “I don’t know”. I am suggesting this because if they do choose that answer they are still able to advance with a solid green. But, it gives no explanation of the correct answer.
Another issue I have seen with the same problem is that it does not allow them to select an answer. Usually, students have to refresh the page before they are able to select.